Toward a global chemogeography of dissolved organic matter: a molecular trait dataset across Earth systems
Year: 2026
Type: preprint
Abstract: Dissolved organic matter (DOM) is a central component of biogeochemical cycling, but molecular observations generated by ultrahigh-resolution mass spectrometry remain fragmented across studies, limiting quantitative comparisons among ecosystems. Here, we compile and harmonize a global dataset of DOM molecular traits comprising 3,999 samples from 337 studies published between 2005 and 2026. The dataset includes eight intensity-weighted molecular traits: hydrogen-to-carbon (H/C), oxygen-to-carbon (O/C), nitrogen-to-carbon (N/C), and sulfur-to-carbon (S/C) ratios; molecular mass; double-bond equivalents (DBE); modified aromaticity index (AI mod ); and nominal oxidation state of carbon (NOSC). Samples span aquatic, terrestrial, atmospheric, plant-associated, petroleum-related, and other environments, and are linked, where available, to geographic, physicochemical, nutrient, and climatic metadata. Molecular data were harmonized using common definitions and restricted to negative-mode electrospray-ionization FT-ICR MS to improve cross-study comparability. This resource enables cross-system comparisons of DOM molecular traits and supports analyses of environmental gradients, geographic coverage, and global DOM chemogeography. Highlights A global dataset of DOM molecular properties was compiled from 3,999 samples reported in 337 publications. The dataset integrates eight sample-level molecular traits: H/C, O/C, N/C, S/C, mass, DBE, AI mod , and NOSC. Samples span six broad Earth-system categories and diverse habitats across land- to-ocean and other environmental settings. Most records are linked to geographic, physicochemical, nutrient, and/or climatic metadata. The dataset supports analyses of DOM chemogeography, habitat-associated variation, environmental drivers, and cross-system convergence.
Authors: Lei Han, Kang Song, James Stegen, Ang Hu
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7214114293